Cider Words: Glucophilic & Fructophilic

Glucophilic and Fructophilic
Glucophilic and Fructophilic

An interesting aspect about yeast is the preference it has for types of sugar. Most yeast prefer glucose so they are what is called glucophilic. The most common fermentation yeast, Saccharomyces cerevisiae, used for wine, beer, and bread is generally glucophilic. While many strains are capble of processing glucose snd fructose, some are highly glucophilic and will not process fructose efficiently. In order to complete fermentation, wine makers may need to add a fructophilic strain to the fermentation process. Fructophilic means the yeast prefers fructose as its primary sugar. This highlights one of the key differences between wine and cider. Besides having much higher levels of total sugars, grape wines contain more glucose versus fructose. Apples on the other hand, contain more fructose.

One of the key genes in yeast that manage the sugar uptake and processing are the HXT genes. Yeast that are fructophilic also have FRT genes that support the transport of fructose into the yeast cells. Starmerella bacillaris, previously known as Candida zemplinina, is a example of a yeast that is fructophilic. It’s a yeast commonly found on grapes, apples, and even prickly pear fruit. Like most non-Saccharomyces yeasts, it was incorrectly considered a spoilage yeast and was sought to be suppressed. We are now understanding the important role non-Saccharomyces yeast can play in the fermentation, stabilization, and quality of wine and cider. It’s the cider part that made me pursue trialing a couple strains from the USDA. Given the level of fructose in apples, it seems like we should be exploring more yeasts that are fructophilic.


Did you enjoy this Mālus Trivium? Don’t miss any future posts, follow me and you will get a link delivered to your inbox. It’s that easy!


Want more details about making and enjoying cider, check out these posts.

2 thoughts on “Cider Words: Glucophilic & Fructophilic

  1. Since I like a sweeter cider, could you recommend the commercial yeasts that are not very fructophilic. So far I found that the yeast that makes the best cider (actually I have made wine in the past instead of cider) has been the wild yeast that lives on my apples.

    Like

    1. I have been testing non-Saccharomyces yeast this year with the main focus on whether they will naturally create residual sugars in cider. These tend to be the yeast found naturally on apples and fruit. Some of these are fructophilic and others glucophilic or both. I have focused on four strains identified in some cider research as having positive aroma and fermentation performance. The thought was that they may have some residual sweetness or produce more glycerol to give that perception. So far, the Pichia kluyveri and Candida zemplinina both finish around 1.000 so I’m calling those unsuccessful in leaving some residual sugars. The Hanseniaspora uvarum are just finishing and show potential as they are starting to clear and around 1.006. I am still getting some activity but they look promising. I will just be starting the Lachancea thermotolarens strains this weekend. I have written about each strain in other articles on the website (search non-Saccharomyces) but I think there is a good chance these or similar yeast could produce a consistent residual sweetness in cider. This may be from its sugar preference, alcohol tolerance, nutrient usage, or a combination of all those. You can get Pichia kluyveri from CHR Hansen. They offer Frootzen. Lachancea thermotolarens is available from CHR Hansen (Concerto) and Lallemand (Philly Sour). The others I have only found through yeast culture labs, like the USDA. More to come as I finish my testing but I do think there are yeast that can do what you desire. There just isn’t much research in finding them because of the focus on wine and beer versus cider.

      Like

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.